Net Promoter Score December 21, 2016 9 min read by Alex

Choose the Best Channel for your NPS Survey

Choose the Best Channel for your NPS Survey

Every business knows that proactively listening to customers and responding to their needs can prove to be a huge competitive advantage. Yet most modern day businesses struggle to understand how their customers really feel about the brand and how they can refine their business model to match those expectations.

While customer satisfaction surveys are a great way to capture the true brand sentiment, the truth is that like all business processes, they need to be fine-tuned to reach the right customer segment, or else they lose their effectiveness.

For instance, imagine a company that has an NPS score of 50 (60% promoters, 10% detractors, 30% passives). Now, based on the score itself, it might feel that the customer satisfaction is high and the company is poised to be a market leader, but what if the administered NPS survey had a poor response rate of only 10%? And what if, out of the 90% non-respondents, there were 10% promoters, 40% passives, and 50% detractors?

That would take the score to -22, instead of +50. That’s what we call response bias. It happens when you don’t administer your survey accurately to reach your target customers. The bias can only be eliminated by improving the response rate and capturing feedback from customers on a consistent basis.

However, figuring out the most effective channels to capture customer feedback can be a challenging task, as businesses have little insights on where and when to survey their customers.

In this article, we look at the four most popular channels (SMS, phone, email, in-app) for running NPS surveys and analyze their effectiveness in capturing customer feedback. The idea is to clearly understand the benefits of each customer feedback channel so that you’re better equipped to develop a plan that best suits your business goals and needs.

1. Text Messages (SMS)

Text messages are something that grabs our attention, something that we all open and reply to. It is the easiest and fastest way to reach out to your customers. And although text messages tend to reach higher response rates, they can be too personal, annoying and intrusive to your clients. To get a clearer idea of whether you want to use text messages for sending your NPS surveys, we listed the advantages and the disadvantages of this channel.


High response rate: Considering the fact that there are officially more mobile devices than people in the world, there’s no undermining the ubiquity of smartphones that have now reached 95.5% of the world population (7.1 billion mobile subscriptions).

If that statistic is not an overwhelming testimony of the popularity of SMS surveys, consider this—text messages have a whopping 98% open rate, which is in sharp contrast to other popular survey channels like emails that have an average of 22% open rate. And since response rate is directly linked with the open-rate, you can expect a much higher response rate by sending out NPS surveys through SMS than other customer feedback channels.

Passive participation: Customers can respond to text messages when they’re comfortable, as text messages do not require active participation. The passivity of the text survey plays a vital role in capturing honest, unbiased customer feedback

Low response time: As it takes little activation energy to respond to a text message than to click on a survey or attend a survey call, the response time for an SMS survey is incredibly low. You get feedback in almost real-time, making it a good choice for administering surveys on a near consistent basis.


Expensive: Customers aren’t going to pay to tell you how they feel about you, which is the reason why you would have to buy a toll-free number that does not charge the customer for responding to text messages. You’ll also have to pay for an SMS service that lets you send messages in bulk, and can reach customers at the right time. Or you can hire an outside company, that will take care of that for you. That makes sending NPS surveys an expensive choice unless you’re already using it to interact with customers on a regular basis.

Narrow dataset: You can only send customer satisfaction surveys to customers who have shared their personal contact information with you, thereby narrowing the outreach of your NPS campaign. Administering your survey on such a narrow dataset can capture feedback with a high degree of non-response bias, as you progressively miss out on capturing the real voice of the customer.

Platform inflexibility: Unlike emails or in-app popups, where users are prompted to click on radio-button or checkboxes to capture their feedback, SMS surveys rely on specific keywords to capture responses. For instance, if customers are prompted with the question, “Would you recommend our brand to your friends/colleagues? Please respond YES or NO”, it’s quite possible that you’ll get responses like “yeah, yea, sure, Ys, yessss,” etc., which do not get recognized by the platform. In other words, if you’re going to use SMS for NPS surveys, you may want to prepare the platform for such data anomalies or leverage the power of natural language processing (NLP).

Advantages and disadvantages of sending customer satisfaction surveys via text messages (SMS)
Advantages and disadvantages of sending customer satisfaction surveys via text messages

Best Suited for: Low trust deficit businesses that support transactions, offer deliveries or other personal services. For instance, banks, e-commerce stores, airlines, telecommunication providers, etc.

2. Phone Calls

Telephone surveys are favored by many businesses since they tend to get a higher response rate due to the more active solicitation of respondents. It’s simple and at the same time efficient. Phone surveys can be divided into two categories: person-to-person and Interactive Voice Response – automated surveys.  Person-to-person surveys are usually conducted by specially trained staff because the quality of the feedback heavily relies on the professionalism of the speakers.


Good response rate: According to the rule of reciprocity in social psychology, it’s hard for a customer to be outright rude if the business shows genuine concern for the customer’s problems.

While emails and text messages are scalable and cost-efficient strategies of administering NPS surveys, it’s a lot easier to ignore a survey email or text message, but quite difficult (and rude!) to hang up on a survey call. However, that dynamic is slowly changing with the advent of spam filtering apps that now alert customers of incoming surveys calls, leading to a reduced response rate.

Provide in-depth insights: Telephone customer satisfaction surveys provide a great opportunity to engage respondents and dive deeper into customer pain points and while getting more in-depth insights. That’s because customers are generally unwilling to provide meticulous details in an email or text message (unless it’s a grievance), but are more than happy to share their thoughts verbally, as spanning into the gory details require little time and effort.


Spark composition effect: When it comes to telephone surveys, the general observation is that people with certain demographic profiles, such as age, are more or less likely to respond to the survey, than other people. This sparks the composition effect, with the survey failing to gather an accurate representation of what the overall audience feels about the brand.

Perhaps, the best example of the composition effect is the U.S presidential election, 2016, where Donald Trump managed to win, despite the fact that almost every pre-election poll predicted Hillary’s victory. According to a study published by HBR, one of the primary reasons why telephone surveys failed to predict the outcome was because a few particular groups systematically excluded themselves from participating in the survey, thereby skewing the aggregated results.

The respondents choose the endpoints of the scale: Another disadvantage of surveying via phone is that there is a high chance that the respondents will choose the endpoints of the scale. In the presentation of a question “On a scale from 1 to 10 where 1 represents “not likely” and 10 represents “very likely”, how likely are you to recommend X to your friends?” respondents have the tendency to pick the first or last options, since it might be the fastest option.

Interviewer bias: The interviewers can present the question with the different intonation and prompts, that might push the respondent toward the desired answer. Also, the presence of an interviewer is known to lead to more positive responses, since most respondents are not fond of saying negative things to live people. For instance, if your flight experience was a nightmare and you decided to never use this airline again. When nicely asked about it by a friendly representative, you might actually answer that the flight was good.

Intrusive: Just like with the text message, calling to a person to get feedback might feel too personal and intrusive. Many people want to keep their lives private and any calls from a company might be perceived as a privacy violation and therefore blocked or added to “do not call” list.

Advantages and disadvantages of conducting customer satisfaction surveys via Phone
Advantages and disadvantages of conducting customer satisfaction surveys via phone

Best Suited for: Low-touchpoint businesses, where customer feedback is critical, but the response rate is inherently low.

3. In-app Surveys

People that landed on your website or use your web or mobile application are probably interested in what you have to offer. As long as you don’t bother them with annoying forms, you can collect insightful feedback that can help you in many ways. Nowadays, it’s used extensively; usually, it’s a pop-up asking one to three questions.

Example of in-app NPS survey
Example of in-app NPS survey

Here are the pluses and minuses of using in-app NPS surveys and some recommendations on when to use it:


Provide contextual insights: Time is an important part of any customer satisfaction survey. Asking restaurant visitors how they felt a month ago when they had lunch is not a smart strategy. An in-app NPS survey is second to none in this regard. The respondents have in front of them both the questionnaire and the presentation website/mobile app.  Therefore, the feedback is specific, fresh, and relevant. On top of that, it’s simple to implement in-app surveys – sometimes a plugin is all you need; plus, it’s cost-effective.

High response rate: The quality and the quantity of in-app survey heavily rely on the traffic of the website/mobile app. But if the visitors are interested in your services or products, it’s quite probable that they will be willing to provide insightful feedback since it is them, who will benefit from the further improvements. The high response rate that in-app NPS surveys deliver can be a good start to effectively close the customer feedback loop.


Does not measure brand loyalty: While in-app surveys provide great contextual insights, the feedback score that customers put on in-app NPS surveys is influenced largely by their most recent transaction or workflow, rather than what they feel about the overall brand experience. That’s in direct contrast with what NPS measures: the loyalty that exists between the company and their customers.

Can feel impersonal: Unlike emails, messages or phone calls that are personalized with customer-specific information, in-app NPS surveys seem too mechanical and impersonal to customers, increasing the probability that they’ll most likely be ignored or disregarded by a significant percentage of customers.

Focus too much on the score: What a customer feels about you while they’re using your product can differ a lot with what they feel a few days or weeks later. And usually what they feel later is more honest than what they feel at the moment. Since the goal of the NPS framework is to proactively elicit key insights from your customers and not to score high on a metric, it makes little sense to boost responsiveness by compromising on qualitative feedback.

Intrusive to the overall user-experience: Depending on how in-app NPS surveys are triggered, they can either improve survey responsiveness or decrease statistical significance. For instance, if you ask your customers to take a survey when they’re in the midst of a highly critical workflow, they’ll most likely close the popup or quickly fast-forward the survey to get back to what they were doing. They’ll also hold back from providing consistent open-ended feedback, which is one of the most important elements of a successful NPS campaign.

Advantages and disadvantages of conducting customer satisfaction surveys in-app
Advantages and disadvantages of conducting customer satisfaction surveys in-app

Best Suited for: SaaS companies or internet businesses, that have regular active users and for whom capturing in-app contextual feedback is critical for customer retention.

4. Emails

Good old emails remain one of the most efficient methods of interaction between a company and its customers. It is a channel that is used extensively for sending NPS surveys, due to the low investment and high productivity for gathering insightful data. However, it is less personal, so the open and response rates aren’t the strong point of email surveys.


Non-intrusive: Just like text messages, customers can respond to your NPS survey when they’re comfortable, as the survey email sits right in their personal inbox. As customers can answer the questions at their own sweet time, it improves the odds of capturing qualitative open-ended feedback, as there’s no pressure or urgency to complete the survey.

Accurately measures customer loyalty: Email surveys measure customers’ loyalty towards your whole company and would not be influenced by recent experiences with a specific aspect of your business, as it would be in the case of in-app surveys.

Ideally, you should be sending NPS surveys 1-2 weeks after the last customer interaction to accurately measure customer loyalty and capture honest open-ended feedback.

Wider outreach: You get the most valuable feedback from your passives or detractors, as they’re the ones who can tell you exactly what’s wrong with your product and how you can improve the customer experience.

Unfortunately, you won’t be able to get these insights through text messages, phone calls or in-app surveys, as you’ll only be surveying regular active customers.

Emails can help you reach recently inactive users and get responses even from customers that have already churned. The gathered feedback can be influential in identifying hidden bottlenecks and preventing churn before it happens.


Low response rate: Given the fact that an average person receives around 140 emails per day, it’s no surprise that customers don’t actively respond to every email that lands up in their personal inbox. While response rates can be improved by sending NPS surveys at the right time, email campaigns simply can’t match up the responsiveness of telephonic or in-app NPS surveys.

High non-response bias: Since customers only open emails from businesses that they know, like and trust, you’ll never be able to interact with a significant percentage of non-respondents or brand detractors, simply because they’ll never respond to your email. To mitigate the effect of non-response bias on your NPS survey, you need to treat non-respondents as 50% passives and 50% detractors.

Advantages and disadvantages of sending customer satisfaction surveys via email
Advantages and disadvantages of sending customer satisfaction surveys via email

Best Suited for: Almost any kind of business that maintains an active subscriber/customer list, and wants to measure brand sentiment.

Solution? Kickstart Your Multi-Channel Survey Strategy

Want to improve the response rate of your survey, while also improving the effective outreach and statistical accuracy? Kickstart your multi-channel NPS campaign.

For example, instead of relying on a single channel for your customers’ satisfaction survey (let’s say — emails), here’s what you can do:

First, reach out to your most active users through in-app surveys. In case they don’t respond to in-app surveys, you send them a follow-up email and ask for their feedback. In rare cases where you still get no response from the customer after 1-2 weeks, you move towards more personal channels like SMS and phone calls (*if it suits your business model) for re-engagement.

The advantage of adopting the funnel approach is that it allows you to gradually administer your survey from a low touchpoint strategy towards a highly personalized strategy, allowing you to reach more customers and improve the response rate while eliminating the risk of survey fatigue and statistical irrelevance.


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